Orthotropic ambipolar diffusion model for γ-manganese dioxide. The role of the reactive sub-surface

Abstract

γ-manganese dioxide is considered as a continuing solid medium, when it is submitted to diffusion laws. These are derived from an appropriate adoptation of “the analytical theory of heat diffusion in the anisotropic medium”. We have taken into account the ambipolar nature of the diffusion and the internal electrical field which accompanies it. The “instantaneous or continuous point source” theory, which gives a physical interpretation to the analytical solution of the heat conduction differential equation, was applied. With this we explain how particles diffuse from the discontinuous reactive area into the γ-MnO2 bulk.